The area coverage in inking zones can be ascertained by scanning the subject matter to be printed in a pattern having a scanning area that is narrower than the width of inker zones. A two-dimensional checkerboard-pattern-like detection of the area coverage in each ink zone can be obtained. The ink distribution, in accordance with the values ascertained from said area coverage, then determines the local ink supply within each ink zone in the distribution of the ink application.
It has previously been proposed --see German Patent Disclosure Documents DE-OS 29 50 6060 and 29 50 650 --to scan films or printing plates for their area coverage by ink zones, using optoelectronic measuring instruments. After integration or adding of the scanned values, presetting information for ink metering elements, are calculated for instance for ink control sliders in inking mechanisms of offset rotary printing presses. The scanning elements each sense over the width of an ink zone, and for a printing press of typical size have a size of 5 mm.times.720 mm. By suitably moving the scanners, or the elements to be scanned, in other words the film or plate, the preset values can be derived for each ink zone from the area coverage of subject matter to be printed. In practice, it has been found that the preset values thus ascertained are not sufficiently accurate, so that expensive readjustments and corrections are necessary, which among other disadvantages lead to increased spoilage and as a result lengthen the printing time required to complete the printing process.